The following information came from HERE, with some editing and information added. Thanks Christian!

THIS MAY NEED UPDATING FOR THE NEW BLACK CRC CARPET

Brands:

BSR, CRC, Jaco:

Pro One is no longer selling to the public, but it and the brands above are all mounted by BSR and use the same foam. The nomenclature of the BSR vs Jaco/CRC is a little different in a few instances but is otherwise the same. The BSR foam consists of three families, and can be identifed as synthetics, naturals, and blends.

Synthetics - The old school, light weight, easy to true "dry feeling" tires. These include tires like CRC/Jaco Yellow (BSR White), Black, Gray, etc. These tires offer the highest wear rate and lowest grip. Many racers continue to use these nder high bite conditions.

Naturals - These tires are usually the best alternative for low bite and asphalt. They include Pink, Magenta, Double Pink, Lilac (BSR Team Purple), Purple, and other tires. These tires provide a ton of grip, but tend to get sticky in high bite conditions. This rubber does not wear as easily, and the cars will pick up gunk and fibers from the carpet under most high bite conditions. This is especially bad if the humidity is high.

Blends - These are the tires most people run today. They were initially called "JFT foam" by some, as it was believed that the tires were the same as the JFT tires. We can divide the blends further into two groups: high rubber and low rubber content. The high rubber would be the new rear Orange and Red from the BSR family, and the low rubber would be the Green and Blue varieties. When, asked about the difference, John Foister from BSR Tires said they came from the same "family" of foam, but they offered different grip. According to John, the Green/Blue has more bite than Orange/Red, but from track testing Oranges offer more bite than Green (being equivalent to in hardness) when the grip is high and absolutely no grip when it is lower. The Orange foam has a denser pore structure and the tire is not as prone to chunking. It is also important to note is that BSR Blue rears are not the same as the BSR Blue fronts!

JFT:

JFT stands for Japan Foam Tire. They started the new wave of foam tires we are all using now (Blue/Blu, Green/Greene, Dbl Blue, etc). These tires are a little different than the BSR tire family, but work in very similar conditions. They offers four varieties A (asphalt), C (carpet), S (???), and R (???). This does not mean that those types only work on that surface, but this is what they recommend.

JFT uses the same foam for fronts and rears if the color is the same.

A: Used on asphalt, considered close to the natural rubber variety and are named consistently with other natural tires.C: Used on carpet, considered a blend.S: Used on carpet?, tires are ???R: Used on carpet?, tires are ???

For setup, the JFT foam seem to generate more bite than the BSR, therefore the car tends to be a little more aggressive.

Ulti:

Ulti is another Japanese brand that offers an array of compounds. They have their own way of rating tires, and are difficult to equate to other brands. They have 4 different varieties, each in varying degrees of hardness.

J: High rubber content tire, similar to Pink/ Magenta. Soft would be close to a pink. These offer the most bite and are great for asphalt/carpet front tire. (J hard being very popular)X: "Balanced" blend, similar to JFT Blue/ Green. Soft is equivalent to Green, medium to Blue in hardness. Great for carpet!Y: High synthetic blend with lower grip, and is not a very popular variety.Z: A very expensive "special" foam that is supposed to be magic on asphalt. Only make it in soft shore.

European tires:

There are many great European foam tire brands that use their own types of foam, as well as traditional foams. SOmeone with more knowledge about them will need to fill this in!

Tire Diameter:

If you are racing on carpet, you have to evaluate how much grip your track has. If your track is low to medium grip, you can run bigger tires. If you are on higher bite you have to cut them smaller, there is simply no way around it. Bigger tires are needed for asphalt, especially in the rear. The larger tires provide much needed lateral bite.

Carpet (mm):

Low - Medium Bite

Front: 42.0 - 42.5
Rear: 42.5 - 43.00

Medium - High Bite

Front: 40.5 - 41.0
Rear: 41.5 - 42.0

Big Race

Front: 39.5 - 40.0
Rear: 40.5 - 41.0

Asphalt (mm):

Parking Lot

Front: 43.0 - 44.0
Rear: 44.0 - 45.0

Prepped High Bite

Front: 42.0 - 43.0
Rear: 43.0 - 44.0

Tire Saucing:

Most facilities have moved towards odorless traction additives such as SXT. Some of additives evaporate very quickly and some do not. This seems to be something that is also dependent on tire compound and ambient temperature. For example, saucing a Green compound seems like it never dries, especially when tjhe temperature is lower. We have found that wiping the tires off 15 minutes before we go run allows the sauce to cure, which makes the car come in much quicker with Green rears. Blue compounds on the other hand, do fine when wiped off right before hitting the track.

Saucing half front and full rear is a good initial starting point. If the front of the car is too agressive you can sauce les than half, or for a shorter amount of time.

Tire Fuzzing:

In conditions of increasing grip, foam tires will somewtimes get sticky and pick up fuzz and debris from the track. This is highly dependent on the rubber sedan tire that is being run at your local track and the compound/ type of foam you are running on you car. The softer the sedan tire and the harder/higher rubber content in your foam tire, trouble with fuzzing seems more likely to occur.

There are ways to get around fuzzing under most conditions, and usually involves the selection of the correct foam compound. The more fuzz you get, the softer/lower rubber content you want to run.

Examples:
Problem: Car fuzzes with Lilac/Team Purple fronts and car starts pushing.
Solution: Use a softer front tire and or different family of foam. Replace it with Blue or Double Blue front.

You may wonder about other compounds out there and if they might be better, trust me, they probably won't be. Even if there are other tires that can be as fast, the synthetic family wears out really fast and the high natural rubber will probably fuzz on you over an 8 minute run. The blends family seems to be the most versatile foam type available today. They last awhile, and sticking to them will make your process of tire selection simpler.

Tire Charts:

BSR/CRC/Jaco

Contact

Corally

JFT (Japan Foam Tire)

Ulti

Enneti (Xceed)

ELECTRONICS:

ESC:

As of now, ROAR is staying 1S (3.7V nominal; 4.2V fully charged) for 1/12. There are many 1S ESC's with a built in BEC so nothing else is required to power the receiver and servo.

If you don't want to lock yourself into a 1S specific ESC, you do have other options! It is possible to use your 2S ESC without a booster or receiver pack, and the ESC simply supplies the lower voltage. If that does not appeal to you, you will need to use an Rx pack or booster. The Rx pack and booster will both supply the receiver with a higher voltage than the 1S pack.

If you decide to use an Rx pack, MAKE SURE TO REMOVE THE RED WIRE FROM THE ESC PLUG THAT GOES INTO THE RECEIVER!!!

If you choose to use a voltage booster, it works exactly how it sounds. Instead of plugging the ESC into the receiver, it plugs into the booster, and the booster plug goes to the ESC, supplying the higher voltage.

John, here is a pic of the TQ booster wired up to my RS, sorry not the cleanest wire job but hopefully you get the idea. The booster is the small white thing next to the receiver. Its really easy to wire up and works great

Awesome, thank a lot. I will have to pick one of those up. Is it pretty self explanatory on how to wire it up? And where is the best place to buy one from? Once again thanks for the help guys.

Very simple, there are two wires(black and red) soder those to the + and - posts on the esc. plug in the booster to the batt slot in your rec, thats it. Leave the esc switch off and when you plug the 1s in your hot and ready to go. The only place I know of is TQ direct http://www.tqcells.com/, if your in the US it takes a little while due to customs hold, I bought mine 6 or 7 months ago but I think I waited a week and a half or two for it to arrive.

Hey there guys, just have a question reguardig lipos in 1/12. Will I have to run a receiver pack to keep voltage throughout the 8 min run? Not sure if speedo matters but I will be running the tekin rs and Fantom lipo. Any help would be wonderfull. Thanks in advance.

Hey John,

If I remember right Spektrum recievers will handle the voltage of a 2s lipo, as will the JR3650 servo. Ive tested my setup with a 2s lipo powering the reciever and everything seems to be fine. I am using a TrueRC 150mah 2s Lipo from TrueRC which is also a lipo from a Micro T truck. I put mini deans on a servo plug, and put micro deans on the lipo that fits snuggly under the steering servo. To run this you have to pull the posotive wire out of the plug for the esc and you still have function of a switch. I havnt ran it for 8 minutes yet, but I plan on it coming in the next couple weeks up at MMR. Also to see how long the lipo reciever pack will take to charge between runs.

I plan on using 1S lipos in my 12r5 soon .
Fact is it will be with a Mamba max esc and a redline 278 which is 7800 KV and probably a booster,
i wonder if this setup will be fine to race with people using 4,5 or 5 turns /nimh on a carpet medium/high size track ?

Hey guys,
I would like some answers to the following questions please:
a] Will there be a hube gap in performance between racers using lipos compared to those using cells?
b] I am using Xceed tyres [soft rears and medium front]. Can I use medium [or same tyre shore for front and rear]?
c] What the best cells for mod racing? I run a 4.5 but only doing 5minutes races atm, but will have to move to 8 minutes races soon...

i have changed set up and everything but now i believe i know what the problem is...i believe my car has an uneven weight problem. a fellow racer ran his 12r5 today and was spinning out also...so do you apply more weight to the rear of the car or do we have our electronics placed incorrectly in the car...let me know...i know the car is stupid fast but i cannot do anything without feathering it in and out of corners...i applied weight to the battery and it helped a little (2oz of weight)...what do i do ..help...

I wouldn't expect misplaced electronics to cause the car to spin out unless you're running all your electronics on one edge of the chassis. As long as its close, even just visually, it should be OK. I'd be looking at other possibilities

like what else...i have tried a number of things and nothing is working...when i was running 4 cell with brushed motor it never spun out..when i switched to single cell lipo it began to spin out..so i changed the set up to a single cell lipo setup and it still spins out..i have tried tire combinations and everything...i am at whits end about it not handling like it used to..do i need to add weight to the rear of the car

i ran yellow and grey today..and the problem still is there..as i stated earlier, another racer is running the one cell lipo set up and he is having the same spinning out problem to one side...so...i have no idea of what the problem is..i am hoping my much relied on rc community can give me a hand...

i ran yellow and grey today..and the problem still is there..as i stated earlier, another racer is running the one cell lipo set up and he is having the same spinning out problem to one side...so...i have no idea of what the problem is..i am hoping my much relied on rc community can give me a hand...

Man. There is nothing more frustrating than an ill handling 1/12th car.

 What is your ride height in the center of the chassis? Maybe it's bottoming out and unloading the tires? Can you see any rubbing or better yet, any traction build up on the bottom of the chassis? You can take a clean white rag, spray it with motor spray and then wipe the bottom of the chassis. Depending on how black the rag is will tell you how bad it's bottoming out on the track. For a perfectly smooth carpet track, I run about 3mm front and 3.5 in the rear. You may want to raise that to 4.0 in the rear and 4.5 in the front. That will take away some steering.

 Is the rear pod free? No binding. If you take the center shock off, the side shock and the side springs off, does the pod freely flop around? With everything hooked back up, do you have about 1.0mm of rear pod droop when you pick up the car and sight along the bottom of the chassis and the bottom motor pod plate from the side?

 Move the weight forward. DO NOT PUT IT IN THE REAR OF THE CAR!! That will only make the car spin out more. If you have ever thrown darts, where is all of the weight in a dart? Thats right, in the front. And when you throw the dart, does it go straight?

 Try putting on a pair of 24 front springs. You have already tried pink rears and purple fronts and the problem is still there. Try 24 front springs.

 Screw the side springs down to where they just touch the chassis. Then back them off a quarter turn. Try lighter side springs

 Put some 10 weight oil in the center shock and an olive/green spring on the center shock.

 Try narrowing the rear track and widening the front track.

 Move all of the caster shims to the back

 Get a good tweak station and check the car every time you go on the track. Just make it a habit.

This is a lot to try so you can try a few at a time but I would start with one part of the chassis and then move to the other. You know. Do the rear adjustments first, try the car and then do the adjustments to the front. You should have the most rear traction with pink rears and purple fronts so I would stay with that tire combo while you are doing these changes. Also, glue the front outside side wall of the front tires. This will decrease front bite.

i appreciate the help from you all..i am quite frustrated with the car...i am not disappointed in the cars performance when set up correctly...i have set the rear very soft but i guess softer could not hurt at all...i do not know what to do at this point...i guess the rc community and my other counterpart at my local track will figure this out and when we do look out xray, bmi, and crc cars...magenta rears are currently being tested...i wonder what the pros are doing about the different weight issues with the cars...i wonder if they had the same problems with it spinning out...